Image pickup system

Abstract

The invention relates to an image pickup system comprising an electronic view finder suitable for achieving compactness and having a sufficient viewing angle of field and satisfactory optical performance. The image pickup system comprises an image pickup device, an image display device for displaying an image, a controller for converting image formation obtained from the image pickup device into a signal that enables the image information to be formed on the image display device, and a viewing optical system for guiding an image displayed on the display device to a viewer's eye. The viewing optical system comprises at least three lenses.

1. An image pickup system comprising an image pickup device, an image display device including a display screen for displaying an image, a controller for converting image information obtained from said image pickup device into a signal that enables said image information to be formed on said image display device, and a viewing optical system for guiding an image displayed on said display device to a viewer's eye, wherein:
 said viewing optical system consists of, in order from said image pickup device side, a negative single-lens component composed of one negative lens element and a positive single-lens component composed of one positive lens element, 
 said negative lens element is a double-concave lens element, 
 said positive lens element is a double-convex lens element, 
 of said negative lens element and said positive lens element, only said positive lens element has an aspheric surface, 
 a light beam from said image display device is guided by refraction alone to said viewer's eye, and 
 the following condition (2) is satisfied:
   1.0 <a/c   (2) 
 
 where a is a the distance from the display screen of said image display device to the surface, nearest to the image display device side, of said viewing optical system, and c is a length of a short side of the display screen of said image display device. 
 
   
   
     2. The image pickup system according to  claim 1 , which satisfies the following condition (1):
   1.0 <b/a   (1) 
 where a is the distance from the display screen of said image display device to the surface, nearest to the image display device side, of said viewing optical system, and b is a total length from the surface, axially nearest to the image display device side, of said viewing optical system to the surface thereof nearest to the viewer side. 
 
   
   
     3. The image pickup system according to  claim 2 , which satisfies the following condition (3):
   1.4 <f   e   /a< 2.4  (3) 
 where a is the distance from the display screen of said image display device to the surface, nearest to the image display device side, of said viewing optical system, and f e  is a focal length of said viewing optical system. 
 
   
   
     4. The image pickup system according to  claim 1  wherein a diagonal length of the display screen of said image display device is in the range of 2.5 mm to 8 mm. 
   
   
     5. The image pickup system according to  claim 1  wherein the angle of field in the diagonal length of the image being observed through said viewing optical system is in the range of 15° to 30°. 
   
   
     6. The image pickup system according to  claim 1 , wherein said image display device is a reflection type image display device for displaying an image by illumination from a display screen side thereof, and said image pickup system further comprises an illumination member for illuminating the display screen of said reflection type image display device. 
   
   
     7. The image pickup system according to  claim 1  which further comprises a phototaking optical system for guiding a light beam to said image pickup device.